Anaplasmosis occurs in mammals, including, e.g., humans, horses, sheep, dogs, cats, deer, and ruminants and is caused by infection of granulocytic cells with the tick-borne agent Anaplasma phagocytophilum (“Aph”) (formerly known as Ehrlichia equi). Common clinical symptoms include fever, lethargy, lameness, thrombocytopenia, swelling of the lymph nodes, and anexoria, all of which are non-specific to anaplasmosis. Therefore a specific test is important for correct diagnosis.
Anaplasma platys (“Apl”) (formerly known as Ehrlichia platys) is a very closely related species. Apl can cause infectious canine cyclic thrombocytopenia (ICCT). Infected dogs are usually asymptomatic in the U.S.A, but may become clinically ill in other parts of the world. Current serologic tests for Anaplasma can not differentiate the two species because of significant cross-reactivity. Methods of detecting Aph and Apl and methods of differentiating between the two infections are needed in the art.
The onset of clinical symptoms occurs during the acute phase of anaplasmosis can precede the advent of measurable levels of antibodies against some Anaplasma antigens. Thus, there is a need for a rapid, sensitive and reliable immunological test for Aph infection, Apl infection, or both, e.g., in mammals exhibiting clinical symptoms of acute anaplasmosis.